Opto-isolator including a vertical cavity surface emitting laser

ABSTRACT

The present invention relates to opto-isolators. Opto-isolators are disclosed that include a transmitter package and a vertical VCSEL disposed within the transmitter package. The opto-isolators further include a receiver package and a photodetector disposed within the receiver package. The photodetector is optically coupled to the VCSEL and configured to receive an output optical signal generated by the VCSEL. The opto-isolators further include an alignment package configured to receive the transmitter package and the receiver package. In another embodiment, opto-isolators include a VCSEL and a photodetector optically coupled to the VCSEL and configured to receive an output optical signal generated by the VCSEL. The opto-isolators further include a package enclosing both the VCSEL and the photodetector.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 60/888,719 filed Feb. 7, 2007. This application alsoclaims the benefit of U.S. Provisional Patent Application No. 60/888,790filed Feb. 8, 2007. The contents of both of the aforementionedprovisional patent applications are hereby incorporated by referenceherein.

BACKGROUND

Electronic noise is one of the limiting factors in today's circuits. Atleast some of the electronic noise typically derives from back enddigital signal processing, typically from the power supply and switchingtransistors. This electronic noise is deleterious to the performance ofanalog integrated circuits.

A device referred to as an opto-isolator (also referred to as an opticalisolator, optocoupler and photocoupler) is often used to reduce noise inelectrical circuits. Opto-isolators electrically isolate portions of acircuit thereby reducing noise. An opto-isolator uses a short opticaltransmission path to transfer a signal between elements of a circuit,typically a LED and a receiver, while keeping them electricallyisolated. The LED and light sensor are separated so that light maytravel across a barrier but electrical current may not. When anelectrical signal is applied to the input of the opto-isolator, the LEDgenerates a light signal, and a light detector generates a correspondingelectrical signal as the output when the LED receives the light signal.When a photodiode is used as the light detector, the output current isproportional to the amount of incident light supplied by the LED. Theratio of the amount of current output by the photodiode to the amount ofcurrent input to the LED is referred to as the current transfer ratio.

Conventional embodiments utilizing LEDs have been limited, however, tolow speed opto-isolation applications because they are limited by theresponse time of the LED. These conventional embodiments have also beenlimited in their current transfer ratio due to high power dissipation ofLED emitters. The subject matter claimed herein is not limited toembodiments that solve any disadvantages or that operate only inenvironments such as those described above. Rather, this background isonly provided to illustrate an example of technology areas where someembodiments may be practiced.

SUMMARY OF THE INVENTION

The present invention relates to opto-isolators. An opto-isolator isdisclosed that includes a transmitter package and a vertical cavitysurface emitting laser (VCSEL) disposed within the transmitter package.The opto-isolator further includes a receiver package and aphotodetector disposed within the receiver package. The photodetector isoptically coupled to the VCSEL and configured to receive an outputoptical signal generated by the VCSEL. The opto-isolator furtherincludes an alignment package configure to receive the transmitterpackage and the receiver package.

In another embodiment, an opto-isolator includes a VCSEL and aphotodetector optically coupled to the VCSEL and configured to receivean output optical signal generated by the VCSEL. The opto-isolatorfurther includes a package enclosing both the VCSEL and thephotodetector.

These and other objects and features of the present invention willbecome more fully apparent from the following description and appendedclaims, or may be learned by the practice of the invention as set forthhereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

To further clarify the above and other advantages and features of thepresent invention, a more particular description of the invention willbe rendered by reference to specific embodiments thereof which areillustrated in the appended drawings. It is appreciated that thesedrawings depict only typical embodiments of the invention and aretherefore not to be considered limiting of its scope. The invention willbe described and explained with additional specificity and detailthrough the use of the accompanying drawings in which:

FIGS. 1-13 disclose example embodiments of opto-isolators;

FIG. 14 discloses an opto-isolator array; and

FIG. 15 discloses a schematic illustration of an opto-isolator circuitwithout a modulation laser driver; and

FIG. 16 illustrates an embodiment of an electronic device.

DETAILED DESCRIPTION OF SEVERAL EMBODIMENTS

The present invention relates to improved opto-isolators. Several of theembodiments disclosed herein relate to opto-isolators having increasedspeed capabilities, lower power dissipation, simplified design, improvedmanufacturability, smaller footprint, lower cost, and/or better currenttransfer ratio as compared to conventional opto-isolators. Inparticular, several opto-isolators disclosed herein may be particularlyadvantageous in certain applications, such as high-speed opticalcommunications, testing equipment (such as high speed oscilloscopes),computing, radio, wireless connections, as well as many otherapplications and circuits. Some embodiments disclosed herein may haveimproved performance characteristics, such as improved response timeenabling high-speed applications and/or improved current transfer ratio,as well as other improvements.

Several opto-isolators described herein include vertical cavity surfaceemitting lasers (VCSELs) as the opto-isolator transmitter in variousintegrated configurations and package designs. The opto-isolatorpackages disclosed herein can include a laser, a photodetector, and alaser driver contained inside a common housing. For example, varioussuch examples and embodiments are disclosed in U.S. patent applicationSer. No. 11/082,521 filed Mar. 17, 2005, the contents of which arehereby incorporated by reference herein. Similar to those embodimentsdisclosed in U.S. patent application Ser. No. 11/082,521, any of thepackages disclosed herein can include a laser, photodetector and a laserdriver within a common housing.

According to several embodiments, a reflective surface can be used toredirect optical signals emitted from a VCSEL such that they arereceived by a photodetector. Embodiments may also include a housingwithin which both the transmitter and receiver are contained. Forexample, the housing can include a package, such as a TO packageincluding a can within which a VCSEL and photodiode are both contained.According to several embodiments, the VCSEL and the photodiode can bearranged in a side-by-side configuration within a can and supported by aheader. Advantages of such embodiments can include simplicity of theopto-isolator design both in use and manufacturing, small size, andreduced cost.

Referring to FIG. 1 an opto-isolator 100 is illustrated according to anexample embodiment. The opto-isolator 100 includes a transmitter opticalsubassembly (TOSA) 105 and an opposing receiver optical subassembly(ROSA) 110. The TOSA 105 includes a VCSEL 115 for generating opticalsignals 125 and the ROSA 110 includes a photodetector 120 for receivingthe optical signals 125 generated by the TOSA 105. The TOSA 105 canfurther include a laser driver 116 for providing a drive current to theVCSEL 115. The laser driver can be located within the TOSA 105. Forexample, the TOSA can include the laser 115, a photodetector 117, andthe laser driver 116 contained inside a common housing, such as theembodiments disclosed in U.S. patent application Ser. No. 11/082,521filed Mar. 17, 2005. The ROSA 110 can also include a transimpedanceamplifier (TIA) 121 packaged in a common housing with the photodetector.According to an example, the TOSA 105 and ROSA 110 can include a TO46type header and can, or other type of package. The packages discussedherein are not limited to TO Can packages but can further include anyother type of package. For example, a T1 type of package can be used.The packages can include plastic encapsulated packages and otherconfigurations of TOSA and ROSA packages with, or without, lenses.

The opto-isolator 100 further includes an alignment package 130. Thealignment package 130 includes a first opening 135 at a first end of thealignment package 130 configured to receive the TOSA 105. The alignmentpackage 130 further includes a second opening 140 opposite to the firstopening 135 at a second end of the alignment package 130 for receivingthe ROSA 110. Thus, the first and second openings 135 and 140 are shapedand configured to receive at least a top portion, such as a can, of thetype of package of the TOSA 105 and ROSA 110.

The alignment package 130 can further include a lens 145 disposedbetween, and separating, the first cavity 135 and the second cavity 140.The lens 145 is configured to collimate, focus, and/or refract theoptical signal output 125 from the TOSA 105 such that the optical signal125 is received by the photodetector 120. The alignment package 130 caninclude, or consist of, any material, such as plastic, and can beunitarily formed as illustrated by FIG. 1. According to an embodiment,the alignment package 130 can include, or consist of, Ultem or apolycarbonate material. In such embodiments, the sidewalls of the firstopening 135 and second opening 140 are formed integral with the lens145.

The alignment package 130 can also include multiple portions assembledtogether. For example, the alignment package 130 can include a hollowportion, which can have a general shape of a tube according to someembodiments, into which a lens is inserted and affixed, thus separatingthe first and second openings 135 and 140. According to an embodiment,at least a portion of the alignment package can be at least partiallyopaque to optical energy. Thus, the opto-isolator may more easilyconform to safety regulations, such as eye safety standards, and otherregulations.

Referring to FIG. 2, another embodiment of an opto-isolator 200 isdisclosed. The embodiment illustrated in FIG. 2 is similar to theembodiment illustrated in FIG. 1 except that the lens 145 (see FIG. 1)has been removed and lenses 205 are coupled with one, both, or neitherof a TOSA 210 and a ROSA 215. According to an embodiment, an alignmentpackage 220 is in the shape of a tube or other cross-sectional shapeconfigured for receiving the TOSA 210 and ROSA 215 packages. Thealignment package 220 can be at least partially opaque to opticalenergy. According to such embodiments, the opto-isolator 200 may moreeasily conform to safety regulations, such as eye safety standards, andother regulations because optical energy can be substantially preventedfrom leaving the interior of the alignment package 220. Additionally, anopaque alignment package 200 also prevents optical energy from beingtransmitted to (and from) other optical circuits causing noise in thosecircuits.

According to additional embodiments, a “sidelooker” package can beimplemented such that the VCSEL and detector are directly opposed.Referring to FIG. 3, a sidelooker package 300 is illustrated where aVCSEL 305 is encased in a first package 310 and a detector 315 isencased in a second package 320. Subsequently, the encased VCSEL 305 andthe encased detector 315 can be aligned, optically coupled, and securedusing a securing agent, such as an optically transmissive UV curableepoxy 325 or other means for retaining alignment and coupling of theencased VCSEL 305 to the encased detector 315. As discussed above, theVCSEL 305, or other portion of the sidelooker package 300, can includelenses, such as wafer level micro-lenses. The sidelooker package 300 canfurther include lenses in one or more of the packages 310 and/or 320 orin the securing agent 325. Circuits including laser drivers, postamplifiers, controllers, and other circuitry can also be included in thepackages 310 and 320 for controlling, or otherwise supporting, the VCSEL305 or the detector 315. The packages 310 and 320 can include anencapsulant or other type of optical package.

FIGS. 4 and 5 are illustrate various embodiments of the opto-isolatorsdisclosed herein. FIG. 4 illustrates an embodiment of a sidelookerpackage. FIG. 5 illustrates an example of a sidelooker package thatincludes a laser driver and TIA circuitry.

Referring to FIG. 6, an opto-isolator 600 is illustrated according to anexample embodiment. As illustrated, the opto-isolator 600 can include aVCSEL 605 optically opposed to a detector 610, such as a PIN photodiodeor other detector. The combination of the VCSEL 605 and detector 610 hasbeen discovered to provide a particularly high speed response time andsuitability for high-speed applications. It has also been discoveredthat in addition to higher response rate for high speed applications,use of the VCSEL 605 in the opto-isolator 600 also can exhibit a highertransfer ratio.

The VCSEL 605 and detector 610 are encased in a single package thatincludes an at least partially optically translucent encapsulant 615.The encapsulant 615 can be at least partially opaque to a particularspectrum of light. For example, the encapsulant 615 can be opaque to afrequency of light commonly found in ambient light that may causeinterference with the transfer of signals 620 from the VCSEL 605 to thedetector 610. The encapsulant 615 may also include multiple portions atleast one portion being opaque to different wavelengths of light thananother portion of the encapsulant. For example, a first portion 625 ofencapsulant 615 directly between the VCSEL 605 and the detector 610 mayby opaque to a first wavelength(s) of light and a second portion 630 ofencapsulant 615 surrounding the VCSEL 605 and the detector 610 andsurrounding the portion 625 of the encapsulant directly between theVCSEL 605 and the detector 610 may be opaque to a second wavelength(s)of light. For example, the portion 625 of the encapsulant 615 betweenthe VCSEL 605 and the detector 610 can be transmissive to the wavelengthof light transmitted by the VCSEL 605. Whereas, the portion 630 of theencapsulant 615 surrounding the VCSEL 605, detector 610, and the portion625 may be non-transmissive to the wavelength of light transmitted bythe VCSEL 605. The portion 630 of the encapsulant 615 surrounding theVCSEL 605 and the detector 610 may also be non-transmissive ofwavelengths of ambient light that may cause interference in thereception of optical signals by the detector 610. By selecting theportion 630 to be non-transmissive of both ambient light and light atthe wavelength transmitted by the VCSEL 605, optical noise is preventedfrom entering the opto-isolator 600 while optical signals generated bythe opto-isolator 600 are prevented from introducing noise into otheroptical circuits.

A portion of the opto-isolator 600 may also include a cavity of air. Forexample, the opto-isolator may be at least partially hollow. The cavityof air may be located so as to allow for transmission of optical signalsthrough air. For example, the portion 625 of the encapsulate 615 may bea void allowing for transmission of optical signals between the VCSELand the detector through the void. The void may be filled with air,another gas, or a vacuum, for example.

Referring to FIG. 7, an opto-isolator 700 is illustrated according toanother example embodiment. The opto-isolator 700 illustrated in FIG. 7includes a VCSEL 705 and a detector 710, such as a PIN photodiode orother detector, encased within a single package that includes anencapsulant 725. The opto-isolator 700 further includes a laser driver715 for providing a drive current to the VCSEL 705. The opto-isolator700 further includes a transimpedance amplifier (TIA) 720 for amplifyinga signal received from the detector 710. Both the laser driver 715 andthe TIA 720 are also encased within the encapsulant 725. Similar to theembodiment discussed above, with reference to FIG. 1, the encapsulant725 can include an at least partially translucent plastic. At least aportion of the encapsulant 725 can also be transmissive to thewavelength of light transmitted by the VCSEL 705 and non-transmissive towavelengths of light other than that transmitted by the VCSEL 705. Theencapsulant 725 can also include a portion between the VCSEL 705 and thedetector 710 which is transmissive to light of the wavelengthtransmitted by the VCSEL 705, and a portion of the encapsulant 725surrounding the VCSEL 705 and the detector 710 can be opaque to variouswavelengths including the wavelength of light transmitted by the VCSEL705 and/or wavelengths of ambient light that may cause interference(e.g. see FIG. 6). By using the laser driver 715 and the TIA 720, a usercan input, for example, logic signal levels (e.g. PECL, TTL) to theopto-isolator 700 and have logic signal levels output by theopto-isolator 700. The ratio of the level of the electrical signaloutput by the opto-isolator 700 to the electrical signals input to theopto-isolator 700 can also be varied by controlling the laser driver 715and/or the TIA 700. For example, in one embodiment, a circuitelectrically connected to the VCSEL 705 may input logic signals of onelogic level in a particular voltage range, while a circuit electricallyconnected to the detector 710 may receive a signal of the same logicallevel, but at a different voltage level. The electronics can incorporateother functions such as logic inversion, and logic adjustment (e.g. TTLto PECL, PECL to LVDS, etc.) which may eliminate the need for otherintegrated circuits.

As discussed above, a portion of the opto-isolator 700 may include avoid for transmission of optical signals. For example, a portion of theencapsulate 725 located between the VCSEL 705 and the detector 710 maybe filled with air such that the optical signal transmitted by the VCSEL705 is transmitted at least partially through air. Lenses, reflectors,refractors, and other optical devices may also be included between theVCSEL 705 and the detector 710 for controlling and directing opticalsignals.

Referring to FIG. 8, an opto-isolator 800 is illustrated according to anexample embodiment. The opto-isolator 800 includes a VCSEL 805 and adetector 810 encased within a package that includes an encapsulant 815.As illustrated in FIG. 8, a lens 820 or other optical collimating,focusing, or refracting device can be coupled to the VCSEL 805. The lens820 can be implemented to improve optical coupling between the VCSEL 805and the optical detector 810. The lens 820 can be integrated with theVCSEL 805 or otherwise optically coupled to the VCSEL 805. For example,the lens 820 can be a wafer integrated micro-optic. Examples of waferintegrated micro-optics are illustrated in U.S. Pat. Nos. 6,909,554 and6,984,076, the contents of both patents are hereby incorporated byreference herein. The lens 820 can be coupled to the surface of theVCSEL 805 from which an optical signal 825 is produced. The optical lens820 can improve the optical coupling of the optical signal 825transmitted from the VCSEL 805 to the detector 810. The encapsulate 815may further include a void as discussed above. For example, a void maybe located at least partially between the VCSEL 805 and the detector810. The lens 820 may or may not be located within the void according tosuch embodiments.

Opto-isolators disclosed herein can include a reflective surface. Thereflective surface may be integrated with the opto-isolator or thereflective surface may be attached to the opto-isolator. For example,referring to FIG. 9 an opto-isolator 900 is illustrated. Theopto-isolator 900 can include a VCSEL 905, detector 910, such as a PINphotodiode or other detector, an optional laser driver 915, and anoptional TIA 920 encased within a package that includes an encapsulant925. The encapsulant 925 can further include, or be coupled to, areflective surface 930. The reflective surface 930 can be, for example,at least partially in the shape of an ellipse, curved, or an at leastpartially spherical structure. The reflective surface 930 can be othergeometrical reflective surfaces including spherical, aspherical,elliptical, and pyramidal reflective surfaces, for example. The VCSEL905 and detector 910 can be positioned relative to the reflectivesurface 930 such that an optical signal 935 transmitted by the VCSEL 905is reflected by the reflective surface 930 and subsequently received bythe detector 910.

The opto-isolator 900 may include a void. For example, the opto-isolator900 may be at least partially hollow such that the optical signal 935 isat least partially transmitted through air. Thus, the reflective surface930 may receive and reflect the optical signal 935 through air, or thereflective surface 930 may receive and reflect the optical signal 935through a material of the encapsulant 925. Additional optical devicesmay be included to control, condition and/or direct the optical signal935.

An opto-isolator can further include multiple reflective surfaces. Forexample, referring to FIG. 10, an opto-isolator 1000 is illustratedaccording to an embodiment. The opto-isolator 1000 includes a VCSEL1005, a detector 1010, such as a PIN photodiode or other detector, anoptional laser driver 1015, and an optional TIA 1020 incorporated withina single package that includes an encapsulant 1025. According to thisembodiment, multiple surfaces 1030 are implemented with the encapsulant1025. For example, at least one reflective surface 1030 may be includedin a reflective structure 1035 incorporated with, or attached to, theencapsulant 1025, so as to redirect an optical signal 1040 generated bythe VCSEL 1005 such that the optical signal 1040 is received by thedetector 1010. According to the embodiment illustrated in FIG. 10, thereflective structure 1035 can include two reflective surfaces 1030 inthe form of a semi-pyramidal structure. The optical signal 1040generated by the VCSEL 1005 is twice redirected such that the opticalsignal 1040 is coupled to the detector 1010. Such an opto-isolator 1000can be implemented in the form of a leadframe optical component havingleads and other electrical connections to the VCSEL 1005 and thedetector 1010.

The opto-isolator 1000 may include a void. For example, theopto-isolator 1000 may be at least partially hollow such that theoptical signal 1040 is at least partially transmitted through air. Thus,the reflective surfaces 1030 may receive and reflect the optical signal1040 through air, or the reflective surfaces 1030 may receive andreflect the optical signal 1040 through a material of the encapsulant1025. Additional optical devices may be included to control, conditionand/or direct the optical signal 1040.

As discussed above, reflective surfaces within an opto-coupler may beused to redirect the optical signals from the optical transmitter to theoptical detector through air (or a vacuum or other gas). For example,FIG. 11 illustrates a surface mount device (SMD) molded cavity package1100 that incorporates reflecting surfaces 1105 disposed in a lid 1110of the package 1100 itself According to this embodiment, the light path1115 is transmitted through air 1120 (as opposed to through material).Thus, any of the embodiments disclosed herein using reflecting surfaceswhere the optical signal is transmitted through material may bereconfigured to implement at least one reflecting surface where theoptical signal is transmitted through air. Using reflective surfaceswhere the optical signal is at least partially transmitted through airmay present advantages in terms of performance. For example, FIG. 11illustrates a square package 1100 with a symmetrical four-sidedreflecting surface 1105 to eliminate the optical and mechanicalorientation requirement in the lid 1110 attachment. The package 1100 canalso be oblong with a two-sided reflecting surface and still have nooptical orientation requirement. This configuration illustrates aninexpensive package, easily tooled for prototypes, and will allow use ofexisting opto-chips. Driver chips for both a VCSEL 1125 and the receiver1130 can also be included within the package 1100.

Referring to FIG. 12, an example of an opto-isolator 1200 is illustratedaccording to an example embodiment. The opto-isolator 1200 includes aVCSEL 1205 and a photodiode 1210 supported by a submount 1215 and aheader 1220. The opto-isolator 1200 further includes a housing 1225. Thehousing 1225 includes, at least one reflective surface 1230 configuredto redirect an optical output signal 1235 generated by the VCSEL 1205such that the optical output signal 1235 is received by thephotodetector 1210. As illustrated in FIG. 12, the housing 1225 may havemultiple reflective surfaces 1230. According to other embodiments, thehousing can have a single conical surface or other surfaces thatredirect the optical output signal 1235 about substantially 180 degrees,or at other angles, such that the optical output signal 1235 is receivedby the photodetector 1210 positioned upon the submount 1215 adjacent tothe VCSEL 1205.

In some embodiments, the submount 1215 may not be necessary. However, insome instances, current may be undesirably coupled through the commonheader 1220. In such instances the use of the submount 1215 isparticularly advantageous. According to the embodiment illustrated inFIG. 12, the submount 1215 can include, or consist of, a material havingpoor current conducting properties, such as for example a ceramicmaterial. Coupling of current can be further reduced by using a ceramicspacer and multiple through leads isolated from the header 1220. Laserdrivers and a TIA may also be included within the housing 1225 asdiscussed in U.S. patent application Ser. No. 11/082,521.

A housing of an opto-isolator package may have any number of reflectivesurfaces configured to redirect an optical output signal from a VCSEL,or other optical transmitter, such that it is received by a photodiode,or other optical receivers. For example, FIG. 13 illustrates anopto-isolator 1300 where a housing 1305 includes a single reflectivesurface 1310. The reflective surface 1310 is configured to redirect anoptical output signal 1315 generated by a VCSEL 1320 such that theoutput optical signal 1315 is received by a photodetector 1325. Thereflective surface(s) of the embodiments disclosed herein can besubstantially or entirely reflective such that light is prevented fromescaping from the interior of the opto-isolator. The reflective surfaces1230 and 1310 of FIGS. 12 and 13 can be made of any material. Forexample, the reflective surfaces 1230 and 1310 can include plastic,metal, or other reflective material. The reflective surfaces 1230 and1310 can be part of the package or can be a separate piece that isattached or otherwise coupled to the package. For example, thereflective surfaces 1230 and 1310 can be a separate piece that issnapped to, or glued to, a TO-Can type (or other type) of opticalpackage.

In some embodiments, multiple opto-isolators can be arranged in a singlepackage. For example, FIG. 14 illustrates an embodiment of a package1400 including an array of opto-isolators 1405 arranged so as to receivesignals from a data bus and transition the signals to another boardwithout the need for a serializer. The opto-isolators 1405 illustratedin FIG. 14 can include any of the opto-isolators disclosed herein,conventional opto-isolators, or any combination thereof.

In some embodiments, the laser driver may be excluded. For example,referring to FIG. 15, a schematic illustration of a circuit illustratinghow a laser driver may not need to be implemented is illustrated. Asshown, a VCSEL 1500 receives a bias current from a power supply 1505.Various combinations of other electronic components 1515, such asresistors, can be implemented to condition the signal. However, themodulation of the VCSEL 1500 is directly controlled by an alternatingcurrent (AC) electrical input 1510. For example, the AC electrical input1510 can be a PECL input, which is an alternating current input. Thealternating current input 1510 can be used as the modulation current ofthe VCSEL 1500 without the requirement of a separate laser driver havingan independent modulation current source.

The opto-isolator embodiments discussed herein can be included with anycircuitry and/or any electronic device. For example, referring to FIG.16 an embodiment of an electronic device 1600 is illustrated accordingto an example embodiment. The electronic device 1600 can include ahigh-speed optical communications device that may be configured totransfer data at a rate of more than 1 Gigabit per second (Gbps). Forexample, the high-speed optical communications device may be configuredto transfer data at a rate of 10 Gbps or more. The electronic device1600 can also include testing equipment, a high speed oscilloscope, acomputer, a radio, a wireless connection, or other circuitry.

The electronic device 1600 includes an opto-isolator 1605 according toany of the embodiments disclosed herein as represented schematically inFIG. 16. The opto-isolator electrically isolates portions of electroniccircuits 1610 and 1615 within the electronic device 1600.

The present invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrativeand not restrictive. The scope of the invention is, therefore, indicatedby the appended claims rather than by the foregoing description. Allchanges which come within the meaning and range of equivalency of theclaims are to be embraced within their scope. Detailed descriptions ofapparatus and processing techniques known in the field of the inventionto one of ordinary skill in the art have been excluded

1. An opto-isolator comprising: a vertical cavity surface emitting laser(VCSEL); a photodetector optically coupled to the VCSEL and configuredto receive an output optical signal generated by the VCSEL; and apackage enclosing the VCSEL and the photodetector, wherein the packageincludes: a first encapsulant encapsulating the VCSEL; a secondencapsulant encapsulating the detector, wherein the first and secondencapsulates are bonded such that the VCSEL and detector are opticallycoupled and secured in an opposed configuration.
 2. An opto-isolatoraccording to claim 1, wherein the first and second encapsulates arebonded together by a substantially clear epoxy.
 3. An opto-isolatoraccording to claim 1, wherein the package includes an encapsulantencasing the VCSEL and the photodetector.
 4. An opto-isolator accordingto claim 1, wherein the opto-isolator further comprises a laser driverenclosed within the package.
 5. An opto-isolator according to claim 1,further comprising a transimpedence amplifier enclosed within thepackage.
 6. An opto-isolator according to claim 1, further comprising amicro-lens coupled to a surface the VCSEL or a surface of the opticaldetector.
 7. An opto-isolator according to claim 1, wherein modulationof the VCSEL is directly controlled by an alternating current electricalinput without a laser driver.
 8. An opto-isolator comprising: a verticalcavity surface emitting laser (VCSEL); a photodetector optically coupledto the VCSEL and configured to receive an output optical signalgenerated by the VCSEL; and a package enclosing the VCSEL and thephotodetector, wherein the package includes in encapsulant that is atleast partially opaque to a particular spectrum or range of spectrums oflight and a first portion of the encapsulant is at least partiallyopaque to a frequency of light generated by the VCSEL, wherein a portionof the encapsulant directly between the VCSEL and the detector is not atleast partially opaque to the frequency of light generated by the VCSEL.